A vertical CsPbBr₃/ZnO heterojunction for photo-sensing lights from UV to green band

Abstract

In this work, we have reported a vertical CsPbBr3/ZnO heterojunction photodetector for photo-sensing lights from UV to visible band. The ZnO thin film is deposited on the c-sapphire substrate through a molecular beam epitaxy (MBE) technique, and then the CsPbBr3 thin film is synthesized on the as-prepared ZnO film layer by using a solution processing method. The as-prepared CsPbBr3/ZnO heterostructure presents type-II energy band structure induced by the energy band offset effect, which can promote the separation and extraction efficiencies of the photo-generated electron-hole pairs. Compared with the CsPbBr3 based metal-semiconductor-metal (MSM) structure photodetector, the heterojunction photodetector presents higher responsivity and detectivity of 630 µA/W and 7 × 109 Jones. While compared with the ZnO based MSM structure photodetector, the heterojunction device reveals much faster response speeds of 61 µs (rise time) and 1.4 ms (decay time). These findings demonstrate that the CsPbBr3/ZnO heterojunction photodetector is promising for constructing next generation perovskite based optoelectronic devices.

Plasmon-enhanced photoresponse and stability of a CsPbBr3 microwire/GaN heterojunction photodetector with surface-modified Ag nanoparticles

“…When contacted with each other in a thermodynamical equilibrium, a depletion layer toward the CsPbBr 3 /GaN interface would be created, thus contributing to the formation of a powerful built-in electric field with the direction of the CsPbBr 3 pointing to GaN. 45,52,53 When reversely biased, the fabricated CsPbBr 3 /GaN heterojunction can be used to detect the incoming lights with photon energies larger than E g,CsPbBr 3 . When illuminated by UV light, the light with energy larger than E g,CsPbBr 3 may be absorbed by the GaN substrate and CsPbBr 3 MW simultaneously.…”

“…As the device is illuminated by visible light, the incoming photons are principally absorbed by the CsPbBr 3 sample, thus contributing to the observed photocurrent. 31,47,52,54 To evaluate the photosensitive capabilities of our fabricated n-CsPbBr 3 MW/p-GaN heterojunction photodetector, we calculated the important figure-of-merit parameters, including spectral responsivity (R), specific detectivity (D*) and external quantum efficiency (EQE). The R is calculated below, 35,48,55…”

“…As the device is illuminated by visible light, the incoming photons are principally absorbed by the CsPbBr 3 sample, thus contributing to the observed photocurrent. 31,47,52,54…”

An In Situ‐Fabricated All‐Inorganic Perovskite/MoO3 Heterojunction by Chemical Vapor Deposition and Its Photoresponse Properties

“…Compared with nanofilms that have low charge separation efficiency owing to quantum confinement effects, CsPbBr 3 microcrystals have a lower trap density, higher carrier mobility, longer carrier diffusion length, and superior performance in terms of defect tolerance and photoelectric conversion, making this a promising material in the field of photoelectric photodetectors (PDs). [1][2][3][4][5][6][7] Heterojunction PDs can compensate for the shortcomings of individual material performance and have higher sensitivity and light response speed compared with photoconductive PDs. [8,9] In heterojunction PDs, the heterojunction acts as the core component for converting optical signals into electrical signals.…”

Sensitization of ZnO Photoconductivity in the Visible Range by Colloidal Cesium Lead Halide Nanocrystals

“…There is also an increasing number of studies considering photoconductive perovskite-containing materials as elements of artificial synapses [ 40 , 41 , 42 , 43 , 44 ]. The published results on the effect of perovskite nanocrystals on the photoconductivity of ZnO mainly concern monohalide perovskites with an organic [ 45 , 46 , 47 , 48 , 49 ] or inorganic cation [ 4 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ], while the use of mixed halide perovskites as sensitizers use is also discussed in the literature [ 44 , 58 , 59 , 60 ], however has not been systematically studied so far.…”